An Automatic Instrument to Study the Spatial Scaling Behavior of Emissivity

Abstract: In this paper, the design of an automatic instrument for measuring the spatialdistribution of land surface emissivity is presented, which makes the direct in situmeasurement of the spatial distribution of emissivity possible. The significance of this newinstrument lies in two aspects. One is that it helps to investigate the spatial scalingbehavior of emissivity and temperature; the other is that, the design of the instrumentprovides theoretical and practical foundations for the implement of measuring distributionof surface emissivity on airborne or spaceborne. To improve the accuracy of themeasurements, the emissivity measurement and its uncertainty are examined in a series ofcarefully designed experiments. The impact of the variation of target temperature and theenvironmental irradiance on the measurement of emissivity is analyzed as well. Inaddition, the ideal temperature difference between hot environment and cool environmentis obtained based on numerical simulations. Finally, the scaling behavior of surfaceemissivity caused by the heterogeneity of target is discussed.